Looseleaf binders, especially those having rings of large diameter, are equipped with sheet lifters for preventing the paper pages of the book from catching under the rings and being torn when the binder is moved from open to closed position.
The conventional sheet lifter comprises a relatively stiff panel with elongated openings through which the rings of the binder extend. The sheet lifter extends for substantially the full height of the sheets that are bound in the binder and extends crosswise of the sheets far enough, when the book is in open position, to raise those portions of the sheets which are in any danger of catching under the rings as the book is closed.
This invention provides a sheet lifter of unique construction with provisions for punching holes in unperforated sheets, with the holes spaced as necessary in order to be bound into the looseleaf binder of which the sheet lifter is a part.
The sheet lifter has the stiffness necessary to perform its lifting function; but it also has a hinge line, some distance from the rings of the binder, about which a flap portion of the sheet lifter can swing into a position overlapping the main body portion of the sheet lifter. Punches on the flap engage openings in the body portion of the sheet lifter to punch holes in a sheet which is placed with its edge embraced between the flap portion and main body portion at the hinge line.
The sheet lifter of this invention is made in such a way that it is inexpensive and flat enough so that it does not interfere with the normal functioning of the sheet lifter.
Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.